Studies will be carried out along three principal lines of research. (1) The mechanism by which solvent components stabilize biopolymers in solution will be investigated further. In particular, the effects of glycerol and sucrose on microtubule stability will be subjected to a rigorous thermodynamic analysis. (2) The mechanism of self-association of tubulin and of its assembly into microtubules will be examined, with particular emphasis on the effects of solvent components on the strength of the interaction and the kinetics of the process. (3) The relation between the circular dichroism of satellite DNAs and first neighbor frequencies in base sequence will be further analyzed in terms of the matrix developed by Allen and Daub, which takes into account homopurine: homopyrimidine stretches.